{
  "columns": {
    "sample_id": {
      "type": "string",
      "required": true,
      "description": "Unique public sample identifier."
    },
    "source_id": {
      "type": "string",
      "required": true,
      "description": "Original specimen, image, or measurement identifier."
    },
    "split": {
      "type": "string",
      "required": true,
      "description": "One of train, validation, test, external_waveplate, external_spectral_*."
    },
    "subset": {
      "type": "string",
      "required": true,
      "description": "One of healthy_bone_cell, waveplate, spectral."
    },
    "specimen_type": {
      "type": "string",
      "required": true,
      "description": "Controlled vocabulary. Current primary split value: healthy_bone_cell."
    },
    "wavelength_nm": {
      "type": "int32",
      "required": false,
      "description": "Measurement wavelength in nanometers. External rows provide this value; healthy_bone_cell rows use null when no single wavelength label is available."
    },
    "patch_id": {
      "type": "string",
      "required": false,
      "description": "Patch identifier for patch-based rows, e.g. patch_0000."
    },
    "target_encoding": {
      "type": "string",
      "required": false,
      "description": "Encoding of target values. Spectral and healthy_bone_cell PNG-derived rows use png_uint8_normalized_to_float32_0_1."
    },
    "plate_type": {
      "type": "string",
      "required": false,
      "description": "Waveplate type for external_waveplate rows, e.g. hwp or qwp."
    },
    "angle_label": {
      "type": "string",
      "required": false,
      "description": "Waveplate angle label from the source folder, e.g. 0deg, n22, p45."
    },
    "angle_deg": {
      "type": "float32",
      "required": false,
      "description": "Waveplate angle in degrees. Labels n22/p22 are interpreted as +/-22.5 degrees; n67/p67 as +/-67.5 degrees."
    },
    "source_path": {
      "type": "string",
      "required": false,
      "description": "Relative source path used during conversion."
    },
    "mueller_shape": {
      "type": "int32[3]",
      "required": true,
      "description": "Stored tensor shape. External waveplate rows are [16, 200, 200]; external_spectral_* and healthy_bone_cell rows are [16, 256, 256]."
    },
    "target_shape": {
      "type": "int32[3]",
      "required": true,
      "description": "Stored tensor shape. External waveplate rows are [6, 200, 200]; external_spectral_* and healthy_bone_cell rows are [6, 256, 256]."
    },
    "mueller": {
      "type": "float32[channel,height,width]",
      "required": true,
      "description": "Channel-first Mueller matrix tensor."
    },
    "target": {
      "type": "float32[channel,height,width]",
      "required": true,
      "description": "Channel-first Lu-Chipman reference output."
    }
  },
  "todo": [
    "Decide whether to include preview_png or summary statistics."
  ]
}